pnfs: allow non page aligned pnfs layout segments

Remove alignment checks that would revert to MDS and change pg_test
to return the max ammount left in the segment (or other pg_test call)
up to size of passed request, or 0 if no space is left.

Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 6ef108b1d85f111e3696b1eda554b8bc4570991f..ce46a417e500566ca914c1dccdadb044c0927945 100644 (file)
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1388,11 +1388,6 @@ pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *pgio, struct nfs_page *r
 
        WARN_ON_ONCE(pgio->pg_lseg != NULL);
 
-       if (req->wb_offset != req->wb_pgbase) {
-               nfs_pageio_reset_read_mds(pgio);
-               return;
-       }
-
        if (pgio->pg_dreq == NULL)
                rd_size = i_size_read(pgio->pg_inode) - req_offset(req);
        else
@@ -1417,11 +1412,6 @@ pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
 {
        WARN_ON_ONCE(pgio->pg_lseg != NULL);
 
-       if (req->wb_offset != req->wb_pgbase) {
-               nfs_pageio_reset_write_mds(pgio);
-               return;
-       }
-
        pgio->pg_lseg = pnfs_update_layout(pgio->pg_inode,
                                           req->wb_context,
                                           req_offset(req),
@@ -1443,9 +1433,9 @@ pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
                     struct nfs_page *req)
 {
        unsigned int size;
+       u64 end;
 
        size = nfs_generic_pg_test(pgio, prev, req);
-
        if (!size)
                return 0;
 
@@ -1463,11 +1453,16 @@ pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
         * first byte that lies outside the pnfs_layout_range. FIXME?
         *
         */
-       if (req_offset(req) >= end_offset(pgio->pg_lseg->pls_range.offset,
-                                        pgio->pg_lseg->pls_range.length))
-               return 0;
+       if (pgio->pg_lseg) {
+               end = end_offset(pgio->pg_lseg->pls_range.offset,
+                                pgio->pg_lseg->pls_range.length);
+               WARN_ON_ONCE(req_offset(req) > end);
+               if (req_offset(req) >= end)
+                       return 0;
+               size = min((unsigned int)(end - req_offset(req)), size);
+       }
 
-       return min(size, req->wb_bytes);
+       return size;
 }
 EXPORT_SYMBOL_GPL(pnfs_generic_pg_test);